Problem: Luis ate 2 slices of pizza. Brandon ate 2 slices. If Luis ate $\dfrac{2}{6}$ of the pizza, what fraction of the pizza was eaten?
If 2 slices represent $\dfrac{2}{6}$ of the pizza, there must have been a total of 6 slices. $\text{fraction of pizza eaten} = \dfrac{\text{number of slices eaten}}{\text{number of slices total}}$ They ate ${4}$ out of $6$ slices. They ate $\dfrac{4}{6}$ of the pizza.